European Journal of Radiology

Editorial Board

2010-01-01

Editorial

Hanna Pohjonen — 2010-01-01

The EU eHealth initiative and action plan is the driving force behind changing the European healthcare IT procurement market. It was launched in 2004 and will be applied in its current form until 2010. Instead of organizational eHealth this initiative encourages development of eHealth on the national level; at the same time the focus is being shifted from in-border health to more integrated healthcare provision across the EU. Teleradiology as a service is a part of broader eHealth services. In this special issue of European Journal of Radiology, the writers study teleradiology from several points of view: technical, functional, legal, security and practical experience.

From shared data to sharing workflow: Merging PACS and teleradiology

Menashe Benjamin, Yinon Aradi, Reuven Shreiber — 2010-01-01

Abstract: Due to a host of technological, interface, operational and workflow limitations, teleradiology and PACS/RIS were historically developed as separate systems serving different purposes. PACS/RIS handled local radiology storage and workflow management while teleradiology addressed remote access to images. Today advanced PACS/RIS support complete site radiology workflow for attending physicians, whether on-site or remote. In parallel, teleradiology has emerged into a service of providing remote, off-hours, coverage for emergency radiology and to a lesser extent subspecialty reading to subscribing sites and radiology groups.When attending radiologists use teleradiology for remote access to a site, they may share all relevant patient data and participate in the site's workflow like their on-site peers. The operation gets cumbersome and time consuming when these radiologists serve multi-sites, each requiring a different remote access, or when the sites do not employ the same PACS/RIS/Reporting Systems and do not share the same ownership. The least efficient operation is of teleradiology companies engaged in reading for multiple facilities. As these services typically employ non-local radiologists, they are allowed to share some of the available patient data necessary to provide an emergency report but, by enlarge, they do not share the workflow of the sites they serve.Radiology stakeholders usually prefer to have their own radiologists perform all radiology tasks including interpretation of off-hour examinations. It is possible with current technology to create a system that combines the benefits of local radiology services to multiple sites with the advantages offered by adding subspecialty and off-hours emergency services through teleradiology. Such a system increases efficiency for the radiology groups by enabling all users, regardless of location, to work “local” and fully participate in the workflow of every site. We refer to such a system as SuperPACS.

The future progress of teleradiology—An empirical study in Sweden

N. Lundberg, M. Wintell, L. Lindsköld — 2010-01-01

Abstract: This paper describes a novel teleradiology solution, its services and graphical user interfaces (GUIs), and the strategic decisions taken in the development of the services. The novel services are embedded in a radiology information infrastructure in Västra Götalandsregionen (VGR), Sweden. The application is fully integrated with all different RIS and PACS systems in the region and interconnected through the radiology information infrastructure. In practice, the solution offers new ways of collaborating through information sharing within a region. Knowledge can be used collectively to improve the radiology workflow and its outcomes for clinicians and patients. The new shared approach marks the beginning of a change from local to enterprise workflow. The challenges are to develop useful and secure services for different groups related to the radiological information infrastructure. It involves continuous negotiation with people concerning how they should collaborate within the region. The need for teleradiology as a service provided “by somebody” has disappeared in VGR; today it is a shared service embedded in the innovative radiology information infrastructure. This infrastructure is just a starting point for a novel and limitless telemedicine service including limitless healthcare actors and activities. The method applied for this study was action research. The study was carried out in collaboration between practitioners and researchers.

Cross-border teleradiology—Experience from two international teleradiology projects

Peeter Ross, Ruth Sepper, Hanna Pohjonen — 2010-01-01

Abstract: Teleradiology aims to even radiologists’ workload, ensure on-call services, reduce waiting lists, consult other specialists and cut costs. Cross-border teleradiology widens this scope beyond the country borders. However, the new service should not reduce the quality of radiology. Quality and trust are key factors in establishment of teleradiology. Additionally there are organizational, technical, legal, security and linguistic issues influencing the service. Herein, we have used experiences from two partially European Union funded telemedicine projects to evaluate factors affecting cross-border teleradiology.Clinical partners from Czech Republic, Denmark, Estonia, Finland, Lithuania and the Netherlands went through 649 radiology test cases in two different teleradiology projects to build trust and agree about the report structure. Technical set-up was established using secure Internet data transfer, streaming technology, integration of workflows and creating structured reporting tool to overcome language barriers.The biggest barrier to overcome in cross-border teleradiology was the language issue. Establishment of the service was technically and semantically successful but limited to knee and hip X-ray examinations only because the structured reporting tool did not cover any other anatomical regions yet.Special attention has to be paid to clinical quality and trust between partners in cross-border teleradiology. Our experience shows that it is achievable. Legal, security and financial aspects are not covered in this paper because today they differ country by country. There is however an European Union level harmonization process started to enable cross-border eHealth in general.

Legal aspects of cross-border teleradiology

Peter M.T. Pattynama — 2010-01-01

Abstract: The growth of cross-border teleradiology has created legal challenges that are insufficiently addressed by nation health laws. New legislation is currently under development at the European level. This article will look at the details of the existing and proposed legislation and the still unsettled issues and will discuss the implications for international teleradiology.

Privacy and security in teleradiology

Pekka Ruotsalainen — 2010-01-01

Abstract: Teleradiology is probably the most successful eHealth service available today. Its business model is based on the remote transmission of radiological images (e.g. X-ray and CT-images) over electronic networks, and on the interpretation of the transmitted images for diagnostic purpose. Two basic service models are commonly used teleradiology today. The most common approach is based on the message paradigm (off-line model), but more developed teleradiology systems are based on the interactive use of PACS/RIS systems. Modern teleradiology is also more and more cross-organisational or even cross-border service between service providers having different jurisdictions and security policies. This paper defines the requirements needed to make different teleradiology models trusted. Those requirements include a common security policy that covers all partners and entities, common security and privacy protection principles and requirements, controlled contracts between partners, and the use of security controls and tools that supporting the common security policy. The security and privacy protection of any teleradiology system must be planned in advance, and the necessary security and privacy enhancing tools should be selected (e.g. strong authentication, data encryption, non-repudiation services and audit-logs) based on the risk analysis and requirements set by the legislation. In any case the teleradiology system should fulfil ethical and regulatory requirements. Certification of the whole teleradiology service system including security and privacy is also proposed. In the future, teleradiology services will be an integrated part of pervasive eHealth. Security requirements for this environment including dynamic and context aware security services are also discussed in this paper.

The value teleradiology represents for Europe: A study of lessons learned in the U.S.

Tiron C.M. Pechet, Greg Girard, Brent Walsh — 2010-01-01

Abstract: Pathology and demography have combined to fuel exponential demand for advanced medical imaging. To support this demand, radiology must move beyond traditional department or modality-based picture archiving and communication systems (PACS) to solutions that ensure access regardless of location. This article delineates underlying reasons for the growth in demand for access to medical imaging in both Europe and the United States. It explains why teleradiology/PACS is critical to support this growth in Europe. It discusses the benefits of and barriers to its widespread implementation as discovered in Canada and the U.S. and how these lessons learned relate to Europe.The article establishes the technological imperatives for teleradiology/PACS and presents three real-world case studies of successful data sharing and shared workflow models via single imaging implementations.Finally, it provides a high-level list of selection criteria for teleradiology/PACS and examines how industry trends affecting the U.S. are important baseline considerations to the success of teleradiology/PACS in Europe.

Preoperative US-guided hook-needle insertion in recurrent lymph nodes of papillary thyroid cancer: A help for the surgeon

2010-01-01

Abstract: Objective: The objective of this study is to investigate whether preoperative ultrasound guided insertion of a hook-needle is useful in reoperations for cervical recurrent lymph node metastases of papillary thyroid cancer.Patients and methods: 8 patients with operated papillary thyroid cancer were included in this study. They all had suspicious nonpalpable cervical lymph nodes discovered during follow-up. These lymph nodes were identified by ultrasound imaging and their metastatic nature was confirmed by fine needle aspiration cytology and measurement of in situ thyroglobulin. In all cases, surgical excision of these lymph nodes was decided. All 8 patients had a hook-needle inserted in the suspicious lymph node(s) preoperatively and under ultrasound guidance.Results and conclusion: In all 8 patients, the suspicious lymph nodes were removed and their metastatic nature was confirmed by the final pathological examination. This localization technique is very helpful for the surgeon during the excision of small and nonpalpable lymph nodes, especially in previously operated area.

Visualization of morphological parenchymal changes in emphysema: Comparison of different MRI sequences to 3D-HRCT

2010-01-01

Abstract: Purpose: Thin-section CT is the modality of choice for morphological imaging the lung parenchyma, while proton-MRI might be used for functional assessment. However, the capability of MRI to visualize morphological parenchymal alterations in emphysema is undetermined. Thus, the aim of the study was to compare different MRI sequences with CT.Materials and methods: 22 patients suffering from emphysema underwent thin-section MSCT serving as a reference. MRI (1.5T) was performed using three different sequences: T2-HASTE in coronal and axial orientation, T1-GRE (VIBE) in axial orientation before and after application of contrast media (ce). All datasets were evaluated by four chest radiologists in consensus for each sequence separately independent from CT. The severity of emphysema, leading type, bronchial wall thickening, fibrotic changes and nodules was analyzed visually on a lobar level.Results: The sensitivity for correct categorization of emphysema severity was 44%, 48% and 41% and the leading type of emphysema was identical to CT in 68%, 55% and 60%, for T2-HASTE, T1-VIBE and T1-ce-VIBE respectively. A bronchial wall thickening was found in 43 lobes in CT and was correctly seen in MRI in 42%, 33% and 26%. Of those 74 lobes presented with fibrotic changes in CT were correctly identified by MRI in 39%, 35% and 58%. Small nodules were mostly underdiagnosed in MRI.Conclusion: MRI matched the CT severity classification and leading type of emphysema in half of the cases. All sequences showed a similar diagnostic performance, however a combination of HASTE and ce-VIBE should be recommended.

The value of positron emission tomography in patients with non-small cell lung cancer

Frank Kee, Sara Erridge, Ian Bradbury, Karen Cairns — 2010-01-01

Abstract: Background: Pre-operative assessment of non-small cell lung cancer (NSCLC) is a major application of positron emission tomography (FDG-PET). Despite substantial evidence of diagnostic accuracy, relatively little attention has been paid to its effects on patient outcomes. This paper addresses this by extending an existing decision model to include patient-elicited utilities.Patients and methods: A decision-tree model of the effect of FDG-PET on pre-operative staging was converted to a Markov model. Utilities for futile and appropriate thoracotomy were elicited from 75 patients undergoing staging investigation for NSCLC. The decision model was then used to estimate the expected value of perfect information (EVPI) associated with three sources of uncertainty—the accuracy of PET, the accuracy of CT and the patient related utility of a futile thoracotomy.Results: The model confirmed the apparent cost-effectiveness of FDG-PET and indicated that the EVPI associated with the utility of futile thoracotomy considerably exceeds that associated with measures of accuracy.Conclusion: The study highlights the importance of patient related utilities in assessing the cost-effectiveness of diagnostic technologies. In the specific case of PET for pre-operative staging of NSCLC, future research effort should focus on such elicitation, rather than further refinement of accuracy estimates.

Lung perfusion CT: The differentiation of cavitary mass

2010-01-01

Abstract: Purpose: To assess the findings of perfusion maps and to evaluate the usefulness of perfusion computed tomography (CT) in the differentiation of cavitary mass.Materials and methods: Fifty-three patients with cavitary lung masses were analyzed. Dynamic chest CT was performed after contrast injection. The volume map, washout map, peak map, and time-to-peak (TTP) map were reformatted using Interactive Data Language (IDL). The perfusion patterns were classified into three scoring groups, and these scorings were repeated after 2-week intervals. Diagnostic confidence levels were assigned by consensus. The kappa statistics was used to determine intraobserver agreement, and Fisher's exact test was used to analyze statistical differences in perfusion scores. Receiver operating characteristic (ROC) analysis was performed to evaluate the usefulness of the perfusion maps.Results: Perfusion maps were reformatted pixel-by-pixel from the time-to-density curve analyses. Pyogenic cavities showed weak washout and slow TTP (69.6%). Conversely, malignant cavities showed strong washout (73.3%). Tuberculous cavities showed low perfusions in the volume and peak maps (66.7%). Intraobserver agreement was excellent. The performance of the combination of CT and perfusion maps was better than that of CT alone.Conclusion: Lung perfusion CT could be a promising and feasible method for differentiation of cavitary mass.

The spectrum of pulmonary sarcoidosis: Variations of high-resolution CT findings and clues for specific diagnosis

Mizuki Nishino, Karen S. Lee, Harumi Itoh, Hiroto Hatabu — 2010-01-01

Abstract: Sarcoidosis is a systemic disease of unknown cause, characterized by widespread non-caseating granulomas. There is a wide spectrum of radiologic manifestations in pulmonary sarcoidosis, providing challenges to radiologists. However, recognition of the key features of sarcoidosis with knowledge of its pathologic background can often allow for specific diagnosis. In this review, we describe the variety of high-resolution CT findings in pulmonary sarcoidosis along with its pathologic features as the basis for radiographic manifestations, and discuss the key features on high-resolution CT for the specific diagnosis of pulmonary sarcoidosis.

Comparing culprit lesions in ST-segment elevation and non-ST-segment elevation acute coronary syndrome with 64-slice multidetector computed tomography

2010-01-01

Abstract: Background: Classifying acute coronary syndrome (ACS) as ST elevation ACS (STE-ACS) or non-ST elevation ACS (NSTE-ACS) is critical for clinical prognosis and therapeutic decision-making. Assessing the differences in composition and configuration of culprit lesions between STE-ACS and NSTE-ACS can clarify their pathophysiologic differences.Objective: This study focused on evaluating the ability of 64-slice multidetector computed tomography (MDCT) to investigate these differences in culprit lesions in patients with STE-ACS and NSTE-ACS.Methods: Of 161 ACS cases admitted, 120 who fit study criteria underwent MDCT and conventional coronary angiography. The following MDCT data were analyzed: calcium volume, Agatston calcium scores, plaque area, plaque burden, remodeling index, and plaque density.Results: The MDCT angiography had a good correlation with conventional coronary angiography regarding the stenotic severity of culprit lesions (r=0.86, p<0.001). The STE-ACS culprit lesions (n=54) had significantly higher luminal area stenosis (78.6±21.2% vs. 66.7±23.9%, p=0.006), larger plaque burden (0.91±0.10 vs. 0.84±0.12, p=0.007) and remodeling index (1.28±0.34 vs. 1.16±0.22, p=0.021) than those with NSTE-ACS (n=66). The percentage of expanding remodeling index (remodeling index >1.05) was significantly higher in the STE-ACS group (81.5% vs. 63.6%, p=0.031). The patients with STE-ACS had significantly lower MDCT density of culprit lesions than patients with NSTE-ACS (25.8±13.9HU vs. 43.5±19.1HU, p<0.001).Conclusions: Sixty-four-slice MDCT can accurately evaluate the stenotic severity and composition of culprit lesions in selected patients with either STE-ACS or NSTE-ACS. Culprit lesions in NSTE-ACS patients had significantly lower luminal area stenosis, plaque burden, remodeling index and higher MDCT density, which possibly reflect differences in the composition of vulnerable culprit plaques and thrombi.

Left ventricular remodelling and systolic function measurement with 64 multi-slice computed tomography versus second harmonic echocardiography in patients with coronary artery disease: A double blind study

2010-01-01

Abstract: The present study evaluated LV volumes, ejection fraction (LVEF) and stroke volume (SV) obtained by 64-MDCT and to compare these data with those obtained by second harmonic 2D Echo, in patients referred for non-invasive coronary vessels evaluation.The most common technique in daily clinical practice used for determination of LV function is two-dimensional echocardiography (2D-TTE). Multi-detector computed tomography (MDCT) is an emerging new technique to detect coronary artery disease (CAD) and was recently proposed to assess LV function.93 patients underwent to 64-MDCT for LV function and volumes assessment by segmental reconstruction algorithm (Argus) and compared with recent (2 months) 2D-TTE, all images were processed and interpreted by two observers blinded to the Echo and MDCT results.A close correlation between TTE and 64 MDCT was demonstrated for the ejection fraction LVEF (r=0.84), end-diastolic volume LVEDV (r=0.80) and end-systolic volume LVESV (r=0.85); acceptable correlation was recruited for stroke volume LVSV (r=0.58). Optimal results were recruited for inter-observer variability for 64-MDCT measured in 45 patients: LVESV (r=0.82, p<0.001), LVEDV (r=0.83, p<0.001), LVEF (r=0.69, p<0.002) and SV (r=0.66, p<0.001).Our results, showed that functional and temporal information contained in a coronary 64-MDCT study can be used to assess left ventricular (LV) systolic function and LV dimensions with good reproducibility and acceptable correlation respect to 2D-TTE. The combination of non-invasive coronary artery imaging and assessment of global LV function might became in the future a fast and conclusive cardiac work-up in patients with CAD.

Left anterior descending coronary artery myocardial bridging by multislice computed tomography: Correlation with clinical findings

2010-01-01

Abstract: Objective: To assess the relationship between left anterior descending (LAD) coronary artery myocardial bridging detected by 64-slice computed tomography (CT) and clinical findings.Methods: 221 consecutive patients were examined with coronary 64-slice CT angiography. 21 patients with coronary stenosis >50% were excluded. The length, depth, and luminal narrowing of LAD myocardial bridges during systole and diastole were measured. CT findings were compared with the treadmill ECG-stress test, and clinical symptoms.Results: Myocardial bridges of the LAD were found in 23% of patients (51/221) (length, 14.9±6.5mm; depth, 2.6±1.6mm). A significant difference was noted between the LAD luminal diameter before the intramyocardial course and intramyocardially, for both diastole and systole (p<0.001); with a higher diameter reduction of 27% for end-systole compared to end-diastole with 15% (p=0.006). Systolic LAD intramyocardial luminal narrowing >50% was found in 3/25 (8%). 30/51 (59%) of bridges were “deep” (>2mm myocardial depth), 21/51 (41%) were “superficial”. The prevalence of a positive ECG-stress tests for the anterior myocardial region was significantly higher in patients with LAD myocardial bridges (34/50; 68%) compared to those without (28/144; 19.4%) (p<0.001). There was no difference between “superficial” and “deep” LAD myocardial bridges in regard to a positive treadmill ECG-stress test. Typical angina was rare with 6%.Conclusion: LAD myocardial bridges are common findings and can possibly explain a positive exercise ECG-stress test for anterior myocardial ischemia. Intramyocardial LAD segments show mild-to-moderate luminal narrowing at rest, which is higher during end-systolic phase.

Correlation between CT patterns and pathological classification of intraductal papillary mucinous neoplasm

Jing Zhang, Pei-jun Wang, Xiao-dong Yuan — 2010-01-01

Abstract: Objective: To examine CT patterns of intraductal papillary mucinous neoplasm (IPMN), analyze their correlation with pathologic classification, and discuss the value of CT in the diagnosis and differential diagnosis of IPMN.Methods: CT patterns of 39 IPMN patients, whose clinical data were complete and whose diagnosis was confirmed by surgery and pathology, were classified into three types: (1) simple main pancreatic duct (MPD) dilation type, (2) MPD dilation with pancreatic cystic lesion type, and (3) simple pancreatic cystic lesion type. Correlations between the three CT types and Takada pathologic classification (MPD type, furcation type and mixture type) were analyzed. The 39 IPMN cases were pathologically classified as the benign group and the malignant/borderline group. CT characteristics including the presence or absence of mural nodules, intrafocal partitions, focal size and the degree of MPD and common bile duct (CBD) dilation were analyzed statistically.Results: A correlation was found between the CT simple MPD dilation type and the pathological MPD type, between the MPD dilation with pancreatic cystic lesion type and the furcation and mixture types, and between the simple cystic lesion type and the furcation type (p<0.001). The benign rate was 92% in patients without intrafocal mural nodules, and 42% in patients with intrafocal mural nodules. The difference between the two groups was statistically significant (p=0.003). The presence or absence of intrafocal partitions was not correlated with benignancy or malignancy (p=0.793). The maximum diameter of malignant/borderline lesions was bigger than that of benign ones (p=0.016). There was no significant difference in MPD and CBD diameters between the benign and malignant/borderline groups. Regardless of pathological classification, the MPD diameter was larger than the CBD diameter in all cases (p=0.02).Conclusion: The three CT types of IPMN well correlated with the pathologic classification, which is helpful for analyzing CT manifestations and improving the accuracy of diagnosis. MPD dilation is usually larger than CBD dilation in IPMN patients, which is also helpful in the diagnosis and differential diagnosis of IPMN in the context of other related findings.

Microinvasive ductal carcinoma in situ: Clinical presentation, imaging features, pathologic findings, and outcome

2010-01-01

Abstract: Objective: The purpose of our study was to describe the clinical features, imaging characteristics, pathologic findings and outcome of microinvasive ductal carcinoma in situ (DCISM).Materials and methods: The records of 21 women diagnosed with microinvasive ductal carcinoma in situ (DCISM) from November 1993 to September 2006 were retrospectively reviewed. The clinical presentation, imaging and histopathologic features, and clinical follow-up were reviewed.Results: The 21 lesions all occurred in women with a mean age of 56 years (range, 27–79 years). Clinical findings were present in ten (48%): 10 with palpable masses, four with associated nipple discharge. Mean lesion size was 21mm (range, 9–65mm). The lesion size in 62% was 15mm or smaller. Mammographic findings were calcifications only in nine (43%) and an associated or other finding in nine (43%) [mass (n=7), asymmetry (n=1), architectural distortion (n=1)]. Three lesions were mammographically occult. Sonographic findings available in 11 lesions showed a solid hypoechoic mass in 10 cases (eight irregular in shape, one round, one oval). One lesion was not seen on sonography. On histopathologic examination, all lesions were diagnosed as DCISM, with a focus of invasive carcinoma less than or equal to 1mm in diameter within an area of DCIS. Sixteen (76%) lesions were high nuclear grade, four (19%) were intermediate and one was low grade (5%). Sixteen (76%) had the presence of necrosis. Positivity for ER and PR was noted in 75% and 38%. Nodal metastasis was present in one case with axillary lymph node dissection. Mean follow-up time for 16 women was 36 months without evidence of local or systemic recurrence. One patient developed a second primary in the contralateral breast 3 years later.Conclusion: The clinical presentation and radiologic appearance of a mass are commonly encountered in DCISM lesions (48% and 57%, respectively), irrespective of lesion size, mimicking findings seen in invasive carcinoma. Despite its potential for nodal metastasis (5% in our series), mean follow-up at 36 months was good with no evidence of local or systemic recurrence at follow-up. Knowledge of these clinical and imaging findings in DCISM lesions may alert the clinician to the possibility of microinvasion and guide appropriate management.

Cine-MRI swallowing evaluation after tongue reconstruction

Dana M. Hartl, Frédéric Kolb, Evelyne Bretagne, François Bidault, Robert Sigal — 2010-01-01

Abstract: Objective: To determine the feasibility of cine-MRI for non-invasive swallowing evaluation after surgery for lingual carcinoma with reconstruction using microvascular free flaps.Methods: Ten patients with stage IV carcinoma of the mobile tongue and/or tongue base treated by surgical resection and reconstruction with a free flap were evaluated after an average of 4.3 years (range: 1.5–11 years), using cine-MRI in “single-shot fast spin echo” (SSFSE) mode. Fiberoptic laryngoscopy of swallowing was performed before MRI to detect aspiration. The tolerance and ability to complete the exam were noted. The mobilities of the oral and pharyngeal structures visualized were evaluated as normal, reduced or increased.Results: Cine-MRI was well tolerated in all cases; “dry” swallow was performed for the 2 patients with clinical aspiration. Tongue base-pharyngeal wall contact was observed in 5 cases. An increased anterior tongue recoil, increased mandibular recoil, increased posterior oropharyngeal wall advancement and an increased laryngeal elevation were observed in 4 cases. One case of a passive “slide” mechanism was observed.Conclusions: Cine-MRI is a safe, non-invasive technique for the evaluation of the mobility of oral and oropharyngeal structures after free-flap reconstruction of the tongue. For selected cases, it may be complementary to clinical examination for evaluation of dysphagia after surgery and free-flap reconstruction. Further technical advances will be necessary before cine-MRI can replace videofluoroscopy, however.

High spatial resolution 3D MR cholangiography with high sampling efficiency technique (SPACE): Comparison of 3T vs. 1.5T

2010-01-01

Abstract: Purpose: The aim of this study was to evaluate image quality of 3D MR cholangiography (MRC) using high sampling efficiency technique (SPACE) at 3T compared with 1.5T.Methods and materials: An IRB approved prospective study was performed with 17 healthy volunteers using both 3 and 1.5T MR scanners. MRC images were obtained with free-breathing navigator-triggered 3D T2-weighted turbo spin-echo sequence with SPACE (TR, >2700ms; TE, 780ms at 3T and 801ms at 1.5T; echo-train length, 121; voxel size, 1.1mm×1.0mm×0.84mm). The common bile duct (CBD) to liver contrast-to-noise ratios (CNRs) were compared between 3 and 1.5T. A five-point scale was used to compare overall image quality and visualization of the third branches of bile duct (B2, B6, and B8). The depiction of cystic duct insertion and the highest order of bile duct visible were also compared. The results were compared using the Wilcoxon signed-ranks test.Results: CNR between the CBD and liver was significantly higher at 3T than 1.5T (p=0.0006). MRC at 3T showed a significantly higher overall image quality (p=0.0215) and clearer visualization of B2 (p=0.0183) and B6 (p=0.0106) than at 1.5T. In all analyses of duct visibility, 3T showed higher scores than 1.5T.Conclusion: 3T MRC using SPACE offered better image quality than 1.5T. SPACE technique facilitated high-resolution 3D MRC with excellent image quality at 3T.

Dynamic measurements of total hepatic blood flow with Phase Contrast MRI

2010-01-01

Abstract: Background/Aims: To measure total hepatic blood flow including portal and proper hepatic artery flows as well as the temporal evolution of the vessel's section during a cardiac cycle.Methods: Twenty healthy subjects, with a mean age of 26 years, were explored. Magnetic resonance imaging blood flow measurements were carried out in the portal vein and the proper hepatic artery. MR studies were performed using a 1.5T imager (General Electric Medical Systems). Gradient-echo 2D Fast Cine Phase Contrast sequences were used with both cardiac and respiratory gatings. Data analysis was performed using a semi-automatic software built in our laboratory.Results: The total hepatic flow rate measured was 1.35±0.18L/min or 19.7±4.6mL/(minkg). The proper hepatic artery provided 19.1% of the total hepatic blood flow entering the liver. Those measurements were in agreement with earlier studies using direct measurements.Mean and maximum velocities were also assessed and a discrepancy between our values and the literature's Doppler data was found.Measurements of the portal vein area have shown a mean variation, defined as a “pulsatility” index of 18% over a cardiac cycle.Conclusions: We report here proper hepatic artery blood flow rate measurements using MRI. Associated with portal flow measurements, we have shown the feasibility of total hepatic flowmetry using a non-invasive and harmless technique.

Differential diagnosis between metastatic tumors and nonsolid benign lesions of the liver using ferucarbotran-enhanced MR imaging

2010-01-01

Abstract: Purpose: To evaluate ability of ferucarbotran-enhanced MR imaging (MRI) in differentiating metastases from nonsolid benign lesions of the liver according to signal-intensity characteristics.Materials and methods: Sixty-six consecutive patients, who had 138 focal hepatic lesions (26 cysts, 11 hemangiomas, and 101 metastases), underwent ferucarbotran-enhanced MRI. The signal-intensity pattern of each kind of lesion relative to the liver parenchyma on ferucarbotran-enhanced T2* and heavily T1-weighted gradient-echo images were assessed and categorized into the following three categories: high-intensity and iso-intensity, respectively (category A), high and low (category B), and iso- and low-intensity (category C). For category B, lesions were subdivided into two groups based on single-shot half-Fourier RARE images: category B1 (not significantly high-intensity) and category B2 (significantly high-intensity).Results: Category A had 11 hemangiomas and 2 metastatic tumors, category B1 had 97 metastatic tumors, category B2 had 2 metastatic tumors and 9 cysts, and category C had 17 cysts. When a tumor with a signal intensity of category A was considered to be hemangioma, category B1 metastasis, and category B2 and C cyst, the diagnostic accuracy for differentiating these lesions was 97% (134/138).Conclusion: The combination of signal-intensity pattern on ferucarbotran-enhanced T2*- and heavily T1-weighted gradient-echo MRI has ability to differentiate liver metastases from nonsolid benign lesions. However, T2-weighted single-shot half-Fourier RARE imaging should also be employed to achieve better performance.

Detection of liver metastases: Gadoxetic acid-enhanced three-dimensional MR imaging versus ferucarbotran-enhanced MR imaging

Young Kon Kim, Young Hwan Lee, Hyo Sung Kwak, Chong Soo Kim, Young Min Han — 2010-01-01

Abstract: Purpose: To compare the diagnostic performance of gadoxetic acid-enhanced MRI with ferucarbotran-enhanced MRI for the detection of liver metastases.Materials and methods: Thirty-six patients with 80 liver metastases who underwent gadoxetic acid-enhanced MRI using a three-dimensional volumetric interpolated technique and ferucarbotran-enhanced MRI with a mean interval of 7 days (range, 5–10 days) were included in this study. Two observers independently interpreted the two sets of images – the gadoxetic acid set (unenhanced, early dynamic and 20min delayed phase images) and the ferucarbotran set (unenhanced and ferucarbotran-enhanced T2*-weighted-gradient echo and T2-weighted turbo spin echo images). Diagnostic accuracy was evaluated using the alternative-free response receiver operator characteristic (ROC) method. Sensitivity and positive predictive value were also evaluated.Results: There was a trend toward increased areas under the ROC curve (Az values) for the gadoxetic acid set (0.950, 0.948) as compared with the ferucarbotran set (0.941 and 0.939) of images, but no significant difference was found for both observers (p<0.05). Sensitivities of the gadoxetic acid set (93.8% and 92.5%) were also slightly better than those of the ferucarbotran set (88.8% and 87.5%) with no significant difference (p=0.13). The two image sets showed similar positive predictive values (98.7% and 98.6%, respectively).Conclusions: Gadoxetic acid-enhanced MRI showed comparable diagnostic performance to ferucarbotran-enhanced MRI for the detection of liver metastases.

New proposal for the staging of nonalcoholic steatohepatitis: Evaluation of liver fibrosis on Gd-EOB-DTPA-enhanced MRI

Natsuko Tsuda, Masahiro Okada, Takamichi Murakami — 2010-01-01

Abstract: Purpose: We investigated whether the gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI was useful for nonalcoholic steatohepatitis (NASH) staging based on the severity of liver fibrosis.Materials and methods: Twenty-one male Sprague–Dawley rats aged 7 weeks, weighing about 150g in NASH group were fed a choline-deficient diet for 4, 7 or 10 weeks, and seven rats in the control group were fed a standard diet (n=7). After the feeding period, the rats were subjected to contrast-enhanced MRI (2D-FLASH; TR/TE=101/2.9ms, flip angle 90°). Gd-DTPA (0.1mmol Gd/kg) and Gd-EOB-DTPA (0.025mmol Gd/kg) were injected at 24-h intervals, and the speed of contrast injection was 1mL/s. Signal intensities of the liver were measured and the relative enhancement (RE), the time of maximum RE (Tmax) and elimination half-life of RE (T1/2) in the liver were compared. The fibrosis rate (%) was calculated with the following formula: fibrosis/whole area×100.Results: The fibrosis rates of each group were as follows: 0.52, 0.79, 2.84, and 0.50% (4, 7, 10 weeks and control groups). The fibrosis rate of the 10 weeks group was significantly higher than the control and 4 or 7 weeks groups. Although there was no difference between the Tmax and T1/2 of each group after Gd-DTPA injection, the Tmax and T1/2 of the 10 weeks group were significantly prolonged in comparison with the control and 4 or 7 weeks groups after Gd-EOB-DTPA injection (p<0.01). There was a significant correlation between the fibrosis rate and Tmax or T1/2 after Gd-EOB-DTPA injection (r=0.90 or 0.97).Conclusion: It was possible to assess the progress of liver fibrosis in NASH by evaluating the signal intensity-time course on Gd-EOB-DTPA-enhanced MRI.

Patient acceptance of MR colonography with improved fecal tagging versus conventional colonoscopy

M.P. Achiam, V. Løgager, E. Chabanova, H.S. Thomsen, J. Rosenberg — 2010-01-01

Abstract: Objective: Conventional colonoscopy (CC) is the gold standard for colonic examinations. However, patient acceptance is not high. Patient acceptance is influenced by several factors, notably anticipation and experience. This has led to the assumption that patient acceptance would be higher in non-invasive examinations such as MR/CT colonography (MRC/CTC) and perhaps even higher without bowel preparation. The purpose of this study was to evaluate patient acceptance of MRC with fecal tagging versus CC.Materials and methods: In a 14-month period, all patients first-time referred to our department for CC were asked to participate in the study. Two days prior to MRC, patients ingested an oral contrast mixture (barium/ferumoxsil) together with four meals each day. Standard bowel purgation was performed before CC. Before and after MRC and CC a number of questions were addressed.Results: Sixty-four (34 men, 30 women) patients referred for CC participated in the study. 27% had some discomfort ingesting the contrast mixture, and 49% had some discomfort with the bowel purgation. As a future colonic examination preference, 71% preferred MRC, 13% preferred CC and 15% had no preference. If MRC was to be performed with bowel purgation, 75% would prefer MRC, 12% would prefer CC and 12% had no preference.Conclusion: This study shows that there is a potential gain in patient acceptance by using MRC for colonic examination, since MRC is considered less painful and less unpleasant than CC. In addition, the results indicate that patients in this study prefer fecal tagging instead of bowel purgation.

Perfusion CT in cirrhotic patients with early stage hepatocellular carcinoma: Assessment of tumor-related vascularization

2010-01-01

Abstract: Purpose: To assess the value of CT-perfusion in determining the quantitative vascularization features of early hepatocellular carcinoma (HCC) in cirrhotic patients.Materials and methods: A total of 35 cirrhotic patients with single histologically proven HCC not exceeding 3cm in diameter underwent conventional triple-phase multidetector computed tomography (MDCT) examination. All patients were also examined with CT-perfusion (CTp) technique after i.v. injection of 50mL of iodinated contrast. Data were analyzed using a dedicated software which generated a quantitative map of liver parenchyma perfusion. The following parameters were assessed: hepatic perfusion (HP); blood volume (BV); arterial perfusion (AP); time to peak (TTP) and hepatic perfusion index (HPI). Univariate Wilcoxon signed rank test was used for statistical analysis.Results: In the 35 HCCs evaluated, the following quantitative data were obtained: HP (mL/s/100g): median=47.0 (1stqt=35.5; 3stqt=61.2); BV (mL/100mg): median=22.5 (1stqt=18.4; 3stqt=27.7); AP (mL/min): median=42.9 (1stqt=35.8; 3stqt=55.6); HPI(%): median=75.3 (1stqt=63.1; 3stqt=100); TTP(s): median=18.7 (1stqt=16.8; 3stqt=24.5). Perfusion values calculated in cirrhotic liver parenchyma were HP: median=10.3 (1stqt=9.1; 3stqt=13.2); BV: median=11.7 (1stqt=9.6; 3stqt=15.5); AP: median=10.4 (1stqt=8.6; 3stqt=11.3); HPI: median=17.5 (1stqt=14.3; 3stqt=19.7); TTP: median=44.6 (1stqt=40.3; 3stqt=50.1). HP, BV, HPI and AP were found to be significantly higher in HCC lesion than in liver parenchyma (p<0.001), while TTP was significantly lower (p<0.001).Conclusion: CT-perfusion technique allows obtaining quantitative information about tumor-related vascularization of early HCC, in patients with liver cirrhosis.

Quantitative contrast enhanced ultrasound of the liver for time intensity curves—Reliability and potential sources of errors

2010-01-01

Abstract: Introduction: Time intensity curves for real-time contrast enhanced low MI ultrasound is a promising technique since it adds objective data to the more subjective conventional contrast enhanced technique. Current developments showed that the amount of uptake in modern targeted therapy strategies correlates with therapy response. Nevertheless no basic research has been done concerning the reliability and validity of the method.Patients and methods: Videos sequences of 31 consecutive patients for at least 60s were recorded. Parameters analysed: area under the curve, maximum intensity, mean transit time, perfusion index, time to peak, rise time. The influence of depth, lateral shift as well as size and shape of the region of interest was analysed.Results: The parameters time to peak and rise time showed a good stability in different depths. Overall there was a variation >50% for all other parameters. Mean transit time, time to peak and rise time were stable from 3 to 10cm depths, whereas all other parameters showed only satisfying results at 4–6cm. Time to peak and rise time were stable as well against lateral shifting whereas all other parameters had again variations over 50%. Size and shape of the region of interest did not influence the results.Discussion: (1) It is important to compare regions of interest, e.g. in a tumour vs. representative parenchyma in the same depths. (2) Time intensity curves should not be analysed in a depth of less than 4cm. (3) The parameters area under the curve, perfusion index and maximum intensity should not be analysed in a depth more than 6cm. (4) Size and shape of a region of interest in liver parenchyma do not affect time intensity curves.

The meniscofibular ligament: An MRI study

Haron Obaid, Louise Gartner, Ali A. Haydar, Tim W.R. Briggs, Asif Saifuddin — 2010-01-01

Abstract: Aim: To describe the appearances and determine the prevalence of the meniscofibular ligament (ligamentum fibulare-MFibL) on MRI of the knee.Subjects and methods: Retrospective observational review of 160 knee MRI studies (152 patients) which was performed for a variety of clinical presentations over a period of 31 months. The images were assessed independently by two musculoskeletal radiology Fellows.Results: The MFibL was optimally visualised on far lateral sagittal oblique fat suppressed PDW FSE images. The MFibL appeared as a curvilinear or straight, hypointense band of variable thickness extending between the inferior margin of the posterior third of the lateral meniscus and the fibular head. The ligament was demonstrated in 42.5% (n=68) of the total knee MRI studies, but this prevalence increased to 63% (56/88) in the presence of fluid in the posterolateral corner of the joint.Conclusion: The MFibL is commonly seen on far lateral fat suppressed oblique sagittal PD weighted MR images, particularly in the presence of fluid in the posterolateral corner, and should be recognised as a normal structure in the posterolateral corner of the knee.

Clear cell renal cell carcinoma: Contrast-enhanced ultrasound features relation to tumor size

Jun Jiang, Yaqing Chen, Yongchang Zhou, Huizhen Zhang — 2010-01-01

Abstract: Objectives: To analyze the contrast-enhanced ultrasound (CEUS) features of clear cell renal cell carcinoma (CCRCC) in relation to tumor size.Materials and methods: The CEUS appearance of 92 CCRCCs confirmed pathologically were retrospectively analyzed. Tumor size was stratified into six groups with a 1cm interval. For each lesion, the degree of enhancement, the homogeneity of enhancement and the presence of pseudocapsule sign were evaluated and compared with the pathologic findings.Results: The tumors of groups I–VI were counted for 13, 26, 21, 11, 10 and 11, respectively. All the CCRCCs mainly showed a marked enhancement, and there was no statistically significance between the degree of enhancement and tumor size (P>0.05). However, both homogeneity of enhancement and frequency of pseudocapsule correlated well with the tumor size (P<0.01). Homogeneous enhancement was shown in 85%, 65%, 19%, 9%, 0% and 0% of the tumors in the six groups, respectively. In tumors ≤3cm the frequency (72%) of homogeneity was significantly higher than in tumors >3cm (9%; P<0.01). The detection rate of pseudocapsule sign in the six group was 23%, 62%, 71%, 64%, 50% and 0%, respectively. The frequency of pseudocapsule sign was significantly higher in tumors 2.1–5cm than <2cm and >5cm (66%, 23%, 24%, respectively; P<0.01). On the pathologic examinations, the mean MVD was significantly higher in marked enhancement tumors than slight enhancement tumors (46.0±15.9, 27.5±8.3, respectively; P<0.01). Any tumors with a heterogeneous enhancement pattern were accompanied by intratumoral necrosis or cysts on histologic specimen. A pseudocapsule was seen at pathology in all the 46 cases with perilesional enhancement and 4 of 46 tumors without perilesional enhancement at CEUS.Conclusion: CEUS features of CCRCCs vary with the size of the tumor, especially in the homogeneity of enhancement and the presence of pseudocapsule sign. CEUS is effective in demonstrating the sonographic visualization of tumoral characteristics.

Dose related, comparative evaluation of a novel bone-subtraction algorithm in 64-row cervico-cranial CT angiography

E. Siebert, G. Bohner, M. Dewey, C. Bauknecht, R. Klingebiel — 2010-01-01

Abstract: Purpose: Comparative evaluation of a low-dose scan protocol for a novel bone-subtraction (BS) algorithm, applicable to 64-row cervico-cranial (cc) CT angiography (MSCTA).Methods and patients: BS algorithm assessment was performed in cadaveric phantom studies by stepwise variation of tube current and head malrotation using a 64-row CT scanner. In order to define minimum dose requirements and the rotation correction capacity, a low dose BS MSCTA protocol was defined and evaluated in 12 patients in comparison to a common manual bone removal algorithm. Standard MIPs of both modalities were evaluated in a blinded manner by two neuroradiologists for image quality composed, of vessel contour sharpness and bony vessel superposition, by using a five-point score each. Effective Dose (E) and data post-processing times were defined.Results: In experimental studies prescan tube current could be cut down to one-sixth of post-contrast scan doses without compromise of bone-subtraction whereas incomplete subtraction appeared from four degrees head malrotation on. Prescan E amounted to additional 1.1mSv (+25%) in clinical studies. BS MSCTA performed significantly superior in terms of bony superposition for vascular segments C3–C7 (p<0.001), V1–V2, V3–V4 (p<0.05, p<0.001 respectively) and the ophthalmic artery (p<0.05), whereas vessel contour sharpness in BS MSCTA only proved superior for arterial segments V3–V4 (p<0.001) and C3–C7 (p<0.001). MBR MSCTA received higher ratings in vessel contour sharpness for C1–C2 (p<0.001), callosomarginal artery (p<0.001), M1, M2, M3 (p<0.001 each) and the basilar artery (p<0.001). Reconstruction times amounted to an average of 1.5 (BS MSCTA) and 3min (MBR MSCTA) respectively.Conclusion: The novel BS algorithm provides superior skull base artery visualisation as compared to common manual bone removal algorithms, increasing the Effective Dose by one-fourth. Yet, inferior vessel contour sharpness was noted intracranially, thus limiting the BS algorithm use to patients with suspected vessel pathology at the skull base level.

Endovascular repair or medical treatment of acute type B aortic dissection? A comparison

2010-01-01

Abstract: Introduction: The aim of this retrospective study was to compare the outcome of thoracic endovascular aortic repair (TEVAR) to that of medical therapy in patients with acute type B aortic dissection (TBD).Materials and methods: From July 1996 to April 2008, 88 patients presenting with acute TBD underwent either TEVAR (group A, n=38) or medical therapy (group B, n=50). Indications for TEVAR were intractable pain, aortic branch compromise resulting in end-organ ischemia, rapid aortic dilatation and rupture. Follow-up was performed postinterventionally, at 3, 6 and 12 months and yearly thereafter and included clinical examinations and computed tomography (CT), as well as aortic diameter measurements and assessment of thrombosis.Results: Mean follow-up was 33 months in group A and 36 months in group B. The overall mortality rate was 23.7% in group A and 24% in group B, where 4 patients died of late aortic rupture. In group A, complications included 9 endoleaks and 4 retrograde type A dissections, 3 patients were converted to open surgery and 2 needed secondary intervention. None of the patients developed paraplegia. In group B, 4 patients were converted to open surgery and 2 to TEVAR. The maximal aortic diameter increased in both groups. Regarding the extent of thrombosis, our analyses showed slightly better overall results after TEVAR, but they also showed a tendency towards approximation between the two groups during follow-up.Conclusion: TEVAR is a feasible treatment option in acute TBD. However, several serious complications may occur during and after TEVAR and it should therefore be reserved to patients with life-threatening symptoms.

An overview of vascular closure devices: What every radiologist should know

L.Q. Hon, A. Ganeshan, S.M. Thomas, D. Warakaulle, J. Jagdish, R. Uberoi — 2010-01-01

Abstract: Haemostatic devices can be categorised according to their mechanism of action into three main types; namely pressure devices, topical haemostatic pads and vascular closure devices (VCD). Of these three categories, it is the development of VCDs that revolutionised management of endovascular procedures. Currently available VCDs fall into three major classes, those that use a collagen plug, those that use clips and those that perform suture closure at the arteriotomy site. This article provides a comprehensive review of the all three classes with examples of commercially available devices.

A cytogenetic approach to the effects of low levels of ionizing radiations on occupationally exposed individuals

Farideh Zakeri, Tomohisa Hirobe — 2010-01-01

Abstract: The aim of the present study was to assess occupationally induced chromosomal damage in hospital workers exposed to low levels of ionizing radiation. Thirty-two interventional cardiologists, 36 nuclear medicine physicians and 33 conventional radiologists were included in this study, along with 35 healthy age- and sex-matched individuals as the control group. We used conventional metaphase chromosome aberration (CA) analysis, cytokinesis-block micronucleus (MN) assay as important biological indicators of ionizing radiation exposure. Occupational dosimetry records were collected over the last year (ranged from 0.25 to 48mSv) and their whole life exposure (ranged from 1.5 to 147mSv). The results showed significantly higher frequencies of dicentric and acentric CAs (p<0.001) and MN (p<0.01) in all exposed groups than in the controls. Taking all the confounding factors into account, no obvious trend of increased chromosomal damages as a function of either duration of employment, exposed dose, sex or age was observed. Interventional cardiologists had the highest rates of CA and MN frequencies between the worker groups, though the differences were not significant. These results indicate that long term exposure to low dose ionizing radiation could result in DNA damage. Hence, the personnel who work in the hospitals should carefully apply the radiation protection procedures.

Hyperpolarized 129Xe dynamic study in mouse lung under spontaneous respiration: Application to murine tumor B16BL6 melanoma

Hirohiko Imai, Atsuomi Kimura, Tsuyoshi Ito, Hideaki Fujiwara — 2010-01-01

Abstract: This is a study on the analysis of hyperpolarized (HP) 129Xe dynamics applied in the lung of a pathological model mouse under spontaneous respiration. A novel parameter k1k2 – a product of the rate constant for Xe transfer from gas to dissolved phase (k1) and from dissolved to gas phase (k2) – was shown to be derived successfully from the analysis of the HP 129Xe dynamic MR experiment in the mouse lung under spontaneous respiration with the aid of a selective pre-saturation technique. A comparative study using healthy mice and model mice induced with lung cancer (by injection of murine tumor B16BL6 melanoma) was performed and a significant difference was found in the k1k2 values of the two groups, that is, 0.020±0.007s−2 (n=4) for healthy mice and 0.032±0.04s−2 (n=3) for lung cancer model mice (p=0.04). Thus, the parameter obtained by our proposed method is considered useful for detection of lung tumors.

Benjamin S. Halpern — 2010-01-01

Direct Diagnosis in Radiology: Pediatric Imaging, authored by G. Staatz, D. Honnef, W. Piroth and T. Radkow is part of the Direct Diagnosis in Radiology series which includes a total of 12 books covering all subspecialties in the field of radiology. The book itself is divided into the following six main parts: lung and mediastinum, cardiovascular system, neck, gastrointestinal tract, urogenital tract, musculoskeletal system and central nervous system.

Stephan Gentzsch — 2010-01-01

Breast Cancer Imaging—A Multidisciplinary, Multimodality Approach is an outstanding book offering the whole spectrum of breast cancer imaging with an intelligent structured case-based format. As a multimodality, multidisciplinary approach for diagnosing breast cancer and assessing its potential spreading throughout the body it represents all imaging modalities including mammography, computed tomography, magnetic resonance imaging, ultrasound and positron emission tomography with additional input from radiation oncology, medical oncology and breast surgery.

Florian Wolf — 2010-01-01

When I received the two-volume book, “Image Guided Interventions” I was really impressed, since I found, in these 1928 pages, information about almost all the important aspects of interventional radiology. The five editors present, together with about 300 contributing authors from all over the world, a new state-of-the-art book about interventional radiology, one of the fastest growing fields in today's medicine.

Christian Loewe — 2010-01-01

Cardiac radiology has shown an extraordinary progress during the last several years, leading to fundamental changes in the management and diagnosis of patients suffering from coronary and/or heart diseases. According to this exciting technical progress and the new applications of MDCT in this field, a number of books have been published during the very few last years about cardiac radiology. However, most of this books focused more or less exclusively on cardiac or coronary radiology, but do not address the relationship between systemic and pulmonary circulation and the consecutive relation between diseases of the lungs and cardiac symptoms or vice versa.

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2010-01-01

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2010-01-01